Do Parkinson's Disease patients disclose Adverse Drug Reactions spontaneously?

SANTIAGO PEREZ-LLORET; VERÓNICA REY; NELLY FABRE; FABIENNE ORY-MAGNE; UMBERTO SPAMPINATO; JEAN-LOUIS MONTASTRUC; OLIVIER RASCOL

Bordeaux, Francia

Congreso; Congreso de Farmacología y Fisiología; 2010

Objective: To explore the gap in the frequency of ADRs to antiparkinsonians when explored by means of a fullexhaustive questionnaire or by the patients´ spontaneous disclosure.Background: Underreporting of adverse drug reactions (ADRs) is generally > 90%. Whether this may be relatedto physicians´ failure to identify ADRs remains unknown. The lack of time during the medical visit may inducephysicians to rely only on patients´ spontaneous ADRs report and not in a systematic evaluation.Methods: Non-demented, non-operated Parkinson´s Disease outpatients of the Toulouse Movement Disorder Clinicwere initially asked to disclose any unpleasant effect in connection with their medication during the last week.Afterwards, they were systematically questioned about the presence of a predefined list of common ADRs toantiparkinsonians. Only ADRs starting within 6 months after causative agent introduction were further analyzed.ADR severity was assessed by the usual pharmacovigilance scale (mild/moderate/severe). Severity of somnolenceor impulse-control disorders was also evaluated by a patient´s auto-administered 10-cm VAS scale. A completemedical and medication history was conducted and a full UPDRS was performed.Results: 98 subjects were recruited (mean age was 67 10 years; 61% were males; UPDRS II and III in ON-statewere 13 7 and 24 9; 7% were on antimuscarinics, 10% on MAOB-I, 15% on amantadine, 21% on COMT-I, 80%on agonists or 90% on levodopa). Sixty-nine out of the 98 subjects (70%) had at least one ADR that started ashort time after introduction of a causative agent, but only 25 of them (36%) disclosed it spontaneously. Thisfigure was essentially similar for the majority of explored ADRs (for example, hypotension symptoms, dry mouth,colored urine, somnolence, vivid dreams, sleep disorders or impulse-control disorders). Nausea/vomiting was theonly ADR reported spontaneously by >75% of the affected patients (7 out of 9 cases). Patients´ failure tospontaneously disclose the ADRs was related to shorter disease duration (p<0.05) but not to ADRs´ severity.Conclusions: The gap between ADRs identified by the full questionnaire or by spontaneous report was 64%, thussuggesting that a pro-active attitude towards the search of ADRs during the medical visit should be adopted.